1. Field of the Invention
The present invention relates to an antenna device for a portable terminal. More particularly the present invention relates to an antenna device mounted on a display element with a flexible functional region.
2. Description of the Related Art
Typically, the term “portable terminal” refers to a device that allows a user to perform a communication function with another user while the user is carrying the portable device. Examples of such communication functions include a voice communication or short message transmission, a data communication function such as the Internet, mobile banking, multimedia file transmission, an entertainment function such as a game, music, or moving image reproduction, and the like. Previously, portable terminals were specialized to perform one of a communication function, a game function, a multimedia function, an electronic scheduler function, etc. However, owing to the development of electric/electronic technologies and communication technologies, it has become possible to implement various functions using a single mobile communication terminal.
As the use of mobile communication terminals is popularized, efforts are continuously made to implement a vehicle or home appliance control function, a transportation fee payment function, a security function, or the like in addition to a communication function through a communication service supplier using a single mobile communication terminal by incorporating a Wireless Local Area Network (WLAN) or Near Field Communication (NFC) function into the mobile communication terminal. Accordingly, the incorporation of various antenna devices into portable terminals is required which are represented by mobile communication terminals. That is, since a mobile communication service, a WLAN communication, and an NFC communication are performed at different frequency bands, an antenna device is required for each communication frequency band.
Further, as the wireless mobile communication is recently turned into the fourth generation system which is represented by Wibro or Long Term Evolution (LTE), a super high speed broadband antenna device is required. Accordingly, portable terminals will require high performance antenna devices with the development of communication technologies. On the other hand, when considering portability, the miniaturization and lightening of portable terminals are essentially required. In addition, as multimedia services through portable terminals are vitalized, a display element capable of providing a screen of a sufficiently large size, which is contradictory to the miniaturization and lightening of portable terminals, is also required.
Recently, research on the commercialization of a display element or a display assembly (hereinafter, referred to as a “flexible display element”) including a flexible functional region are being actively carried out. A flexible display element is useful for securing portability while providing a sufficiently large screen since it may be carried by folding or rolling it in a cylindrical shape or the like. Meanwhile, in the fourth generation mobile communication system, the incorporation of a super high speed broadband antenna device into portable terminals is required. A Multiple Input Multiple Output (MIMO) antenna device is configured such that a plurality of antennas use the same frequency and independently transmit/receive a signal. Such a MIMO antenna device may innovatively increase transmission speed depending on the number of transmittable/receivable antenna elements, i.e., radiators.
However, when a plurality of antenna elements are disposed in a portable terminal provided with a flexible display element, the positions of the antenna elements when the flexible display element is folded or rolled may change. Accordingly, there is a disadvantage in that the transmission/reception performance of the entire antenna device cannot be constantly maintained. That is, antenna devices are usually designed in a condition where transmission/reception is carried out in a state where the display element is extended. However, since the display element and hence the entirety of the portable terminal may be folded or rolled, the operation environment of the antenna device is varied, and thus, the transmission/reception performance of the antenna device may deteriorate. Further, there is a problem in that, when antenna elements that form the MIMO antenna overlap each other in the folded state, the performance deterioration of the antenna device becomes more serious.
Accordingly, there is a need for an improved antenna element combined with a display element or a display assembly in which the performance of the antenna element is prevented from deteriorating even if the display element or the display assembly changes its shape.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.